codemode

Codemode (Experimental)

Codemode lets LLMs write and execute code that orchestrates your tools, instead of calling them one at a time. Inspired by CodeAct, it works because LLMs are better at writing code than making individual tool calls — they have seen millions of lines of real-world TypeScript but only contrived tool-calling examples.

The @cloudflare/codemode package converts your tools into typed TypeScript APIs, gives the LLM a single "write code" tool, and executes the generated code in a secure, isolated Worker sandbox.

Experimental — this feature may have breaking changes in future releases. Use with caution in production.

When to use Codemode

Codemode is most useful when the LLM needs to:

• Chain multiple tool calls with logic between them (conditionals, loops, error handling)
• Compose results from different tools before returning
• Work with MCP servers that expose many fine-grained operations
• Perform multi-step workflows that would require many round-trips with standard tool calling

For simple, single tool calls, standard AI SDK tool calling is simpler and sufficient.

Installation

npm install @cloudflare/codemode ai zod

Quick start

1. Define your tools

Use the standard AI SDK tool() function:

import { tool } from "ai";
import { z } from "zod";

const tools = {
  getWeather: tool({
    description: "Get weather for a location",
    inputSchema: z.object({ location: z.string() }),
    execute: async ({ location }) => `Weather in ${location}: 72°F, sunny`
  }),
  sendEmail: tool({
    description: "Send an email",
    inputSchema: z.object({
      to: z.string(),
      subject: z.string(),
      body: z.string()
    }),
    execute: async ({ to, subject, body }) => `Email sent to ${to}`
  })
};

2. Create the codemode tool

createCodeTool takes your tools and an executor, and returns a single AI SDK tool:

import { createCodeTool } from "@cloudflare/codemode/ai";
import { DynamicWorkerExecutor } from "@cloudflare/codemode";

const executor = new DynamicWorkerExecutor({
  loader: env.LOADER
});

const codemode = createCodeTool({ tools, executor });